


Rin's life as a demon king

by Autumnflower2006



Category: Ao no Exorcist | Blue Exorcist
Genre: A lot of family moments, But basically crack, Crown Prince!Rin, Demon brothers act like demon brothers, Finally, Fluff and Crack, Gen, Humor, Kind!Satan, King of Gehenna Okumura Rin, Okumura Rin was Raised in Gehenna, Satan dad, Yuri is alive!
Language: English
Status: In-Progress
Published: 2019-08-14
Updated: 2019-08-19
Packaged: 2020-08-20 18:14:36
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 4
Words: 3,633
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/20232208
Author URL: https://archiveofourown.org/users/Autumnflower2006/pseuds/Autumnflower2006
Summary: Rin was abducted to Gehenna after his birth in Assiah. At the age of ten he visited Assiah for the second time and was taken back to Gehenna after a few incidents. But the father and son duo made a promise.Now 16, Rin was granted the permission to go back to Assiah! With three depressed older brothers trailing after him.





	1. The Crowning Ceremony of Disaster

**Author's Note:**

> Well, this is my other work from Wattpad! But I am gonna rewrite some chapters.... The first chapters from the first version are really hard to look at.... So I will sometimes rewrite whole chapters or just a few paragraphs. 
> 
> If you don't follow my work in Wattpad you'll be glad to first see it here... the first chapter is very cringy there!

Gehenna. A place where the rebels, who defied against the will of god, resided and ruled. There existed lands that were deserted and filled with the dust of bones from the corpses of powerful forgotten demons that turned into the dust of the desert in the time span of thousands of years, seemingly abandoned normal town filled with lonesome spirits that were secluded and forsaken, holes and spaces filled with ravaging rivers and floods of hot burning and bubbling lava, turbulent seas of crimson blood and the scarlet liquid that fall from the never-ending crimson clouds that come from the west and humid jungles with gigantic trees and man-eating plants that stretch into the far distance. 

And that wasn't all. In every center of those dangerous and life-threatening territory was a massive castle that was visible for all of the demons that lived in the certain area. The royal castle of the ruling king of the territory, so they call it. Based on the territory and on what they specialize in, they call each of their formidable kings different names. For example, King Iblis has been known to be the best fire bender of Gehenna and has been ruling the "The lands of the eternal flame", hence his most well-known name, King of Fire.

Gehenna has existed for a very long time, basically after Satan, their supreme High King, was banished from heaven. Even after billions of years, Satan was still the High King of Gehenna. No one could match him except for God himself. Of course he birthed heirs. Heirs that stand undefeated amongst the others of the same age. Geniuses. Well, naturally because they were connected to the High King by blood! 

Eight of them to be exact. Each of the proud heirs of Gehenna rule a territory in which they specialize in. All of them were biologically connected to Satan, but none of them inherited his most powerful and unstoppable weapon. 

The blue flames. 

He was the only one to wield and control his flames that can burn anything and everything. The flames that made demons respect and fear their mighty ruler. The High King resides in the royal castle in the capital city of Gehenna, where demons with any and all shape, sizes and abilities can find themselves at home, Pandæmonium. Or what others may call, "The capital of the Fallen". 

The demons were used to the eight kings of the territories and their powerful High King at the top that they didn't think they would get a new one so soon. 

The ninth king of Gehenna. 

When word spread out many demons couldn't believe it at first. A new king? Exciting! 

The last time a new king was born a new territory formed in the edges of their world, resulting the demons to take more control of some of the areas in Assiah and new demons were born with it. Well, that was a few thousand years ago where the humans weren't so advanced in their technology, resulting in the advantage that demons had back in the day. But now they really need back up. 

Because of that of course they would get curious as to whom the High King would set the crown on this time and what new demons and their powers would be like. 

Almost all of the demons received the invitation to the crowning ceremony of the ninth king and went to the capital. The demons that were residing in Assiah also returned to celebrate and see this rare occasion of a crowning. 

The capital was livelier than ever. With demons shaped like birds flying high above the ground and demons who walk by foot covered the entire Pandæmonium. Naturally the royal family had to be there too. 

At the massive balcony of the royal castle of the High King they stood proudly, everyone of them. The kings of the territories, the queens who birthed them, high class nobles who serve the High King and the High King only and many more important figures of Gehenna who made history. The only ones who weren't on ceremony were the High King and the ninth king. The two most important characters of the ceremony themselves! 

"Ne Papa, where is Sir High King?" 

"I can't see them either!" 

It was time. The lowly commoners who were far from the royal castle and couldn't go there themselves wondered where they were, since they weren't with the other kings and queens. They were only watching from their communication devices inspired from Assiah to see this live broadcast. 

"You got to be kidding me! Is this stupid thing broken? I thought this was live!" 

"Honey, I think the shop keeper scammed us..." 

"That's right! I don't believe they were ever this late! Trust me, I've been living in Gehenna a few thousand years already! A few hours has already passed! There has never been a crowning ceremony this late without an announcement!" 

"Papa, when can I watch?" 

"Later." 

It was very obvious that this ceremony was very important. Many "online" viewers cursed at their screens, some of them even breaking it in the process. The ones possessing such a device known as the television has decreased by a lot in the matter of an hour. 

Give us back our money! We want our money back! This is bull! 

This has naturally increased the hate that they have for the humans. 

"Pathetic! If I knew the humans would be so stupid to actually make devices that are supposed to go live not live, I would have barged in that insanely large crowd in the first place!" 

They didn't know that it really was live... 

This has caused a huge uproar in the entire capital. 

The kings of the territories looked at each other with an understanding gaze. A few of them shook their heads. That was until one of them tapped the Queen's shoulder, giving her a nod. 

The current wife of the High King sighed and stepped off the podium, her aura slowly scaring the others that were standing beside her a few moments ago into slowly backing away form her. Time to get these two idiots that were fooling around.

**Notes for the Chapter:**

> This will either be half serious or crack...
> 
> Well, I wanted to start this as a serious fic at first.... buuuuut the the crack kicked in and it got to me....
> 
> Sorry?


	2. Royally screwed indeed

**Summary for the Chapter:**

> Father son duo is royally screwed.

"Rin! Come down from there!"

"Never, never! Not coming down!"

"C' mon buddy! For me?"

"Never! I won't wear that!"

"But Rin, you have to! Mommy will get angry~"

"No! I bet you won't fly fast enough to catch me, daddy!"

"Oh~ Was that a challenge?"

"Hehe~, I bet even Mommy is better than you!"

"Ah, this kid... I'm gonna get you!"

"Never!"

Two demons flew in breakneck speed across the hallways. The usually perfectly decorated hallways were made to a complete mess. When they flew past, royal blue curtains and table cloths all got blown away. The duo didn't even look where they were flying, their gigantic ebony wings knocking down the perfectly placed beautiful man-eating plants from the dark wood tables. Even the flaming neon blue torches that lit up the hallways weren't spared and were instantly extinguished. 

Servants that were preparing for the feast after the crowning saw the scene of their very noble High King chasing the soon ninth king of Gehenna around the castle and basically destroying everything in their paths and face-palmed. The father and son were currently at the main celebratory hall, ruining the royal servants' work. The tables that were finely decorated with the most exquisite blue flowers that were very rare to find, since most of the plants were flesh-eaters, golden tableware beside the snow-white plates made from the finest of the land and the tablecloth light blue silk, woven from the old demon masters.

Sadly, everything is ruined. **_Sigh._**

"Not again..."

"Well, this _is_ the young Lord we are talking about."

"Uhm, does this always happen?"

The old servants looked at the young demon maid, holding her broom loosely. One sighed and grasped the maid's shoulders with his sharp green claws.

"Young lad, get used to it soon and be as quick as possible. We keep the High King's.." he paused, " quirk a secret. If any of the nobles get wind of this they'll-"

Suddenly the main door slammed open. The duo froze and slowly their gaze towards the door and gulped.

Oops?

"**CRAP**, _flap them little baby demon_ **FLAP THEM**!"

"**_I'M FLAPPING THEM_**!"

As soon as they came they were gone, back to destroying the hallways. The servants looked at the demon at the door and instantly knew what was going on. "Your Highness-" It was their Queen, clad in light blue armor, clearly not pleased. She gave a frosty smile and extended her raven wings, creating a strong wind.

The servants panicked.

This is bad! The High Queen is angry!

* * *

In a silent room, two kings were hiding behind a large wooden study table stock still. Like any room of the royal castle, it is _gigantic. _Every single room of the castle is decorated to it's finest. The High Queen didn't spare any expenses when attempting to lighten the castle up a bit, thus the demons who came to visit were definitely impressed. It's designed to be a study room, carpeted with royal blue carpeting and curtains that look similar to the blue flames that symbolized the royal family. How the furniture was and how it was placed was based on the Victorian style from back then.

Very classy indeed.

The two were crammed below the large wooden table. As a table inspired from the victorian age it should have been big enough to fit these two, since one is a child that barely reached ten and a very lean adult that practically has the physical build of a teenager. That being said, it should be possible that they could safely avoid detection from the angry High Queen that is currently chasing them, right?

Well, let's not forget the couple meter long wings on their back that they couldn't re-track because of a damn cool-down that nobody likes. Black ebony feathers were littered all over the carpeted floor. 

Rin moved uncomfortably.

"Oi, stop moving around kid."

"I can't help it... it's so _stuffy_ here!"

"Shhhh! Do you want your mother to find us?!"

At that moment, as someone had predicted it, the door creaked open and a bit of light shone through. The figure who opened the door produced a large shadow, a humanoid figure with feathery wings slowly making it's way to the table.

That's when the duo knew...

They screwed up.

** _Slam!_ **

"So, my _boys_, what did I tell you earlier? Huh?"

Being stuck in an awkward situation with his father, that totally looks like a teenager, in a cramped up space by his mother who is like the devil's wife, which she literally is actually, and is really strict with schedules.

The father-son duo's faces paled. They discovered after a lot of times that they got in trouble that when Yuri calls them two "boys" that indicates that she was angry.

_Very_ angry.

They knew they were in a very precarious situation.

"Ne, why don't you two _boys_ come outside and explain."

Hai royally screwed indeed.

**Notes for the Chapter:**

> This is not edited. I repeat this is not edited.


	3. The Crown Prince

**Summary for the Chapter:**

> A crowning that will be remembered for eternity...

**Notes for the Chapter:**

> So, last time the two idiots got caught~
> 
> Yeah, that's to be expected, since Yuri became queen Satan really had no freedom. He really wanted to cry but had no tears left to shed! Rin? What about Rin?
> 
> He's just following his father's footsteps!
> 
> Like father like son indeed.
> 
> Just to notify you all, yes I have read the manga and it's terribly outcomes. Yes, I am knowledgeable of all the...
> 
> Bad stuff that happens there.
> 
> And you know what? I will throw them out of the window. Yes, that's right! Throw them out! 'Cause this is FANON! CANON was thrown out of the window! 
> 
> Done!

"Pawns, slaves, commoners, nobles and kings and queens of this mighty kingdom of mine, here I present you the ninth king, your undoubted king!"

A lean demon that looks like a teenager stood on the highest podium, with the kings of the territories, yes, even Samuel and Lucifer, who spent most of their times in Assiah, and the High Queen calmly standing behind him, her hands behind her back and now wearing a light blue décolleté dress that shows her snow-white skin that contrasted with her pitch-black hair carelessly curled on her shoulder and piercing blue eyes.

Yes, the demon on the podium is the High King, Satan, in all his glory! With a normal school-uniform like suit, he looks like a very normal high school student. Other than his power, many demons admire him for his ability to look like humans, a perfect disguise if you ask them!

If only he could go to the human world without burning his vessel into ash.

"Today we are gathered here to celebrate the crowning of the ninth king of Gehenna!", the High King's voice boomed across the capital, exciting many demons.

"On this day, I am as pleased to say that I, High King of Gehenna, shall take the reins of this ceremony!", he paused," Which mean I will be the one who will eventually crown him!"

Hearing the enthusiastic cheer behind the wooden door leading to the podiums, Rin pulled on his very uncomfortable necktie.

So annoying. Can't he just have a normal crowning? Like the crowning ceremony of Abaddon, his teacher? Can't his father just make a demon official or something to crown him instead? Very annoying indeed. Now his father is just showing off! Is it another punishment for him?

_Seriously! After what mother made me wear... father I thought you were on my side!_

After Rin and his father got caught his mother forced him to wear a stupid suit. I mean, he kind of liked the design and how it looks like. Especially the cape! And it also comes with- No!

Rin you're supposed to hate it!

The ninth king-to-be slapped his forehead. Is he really acting like the rebellious kid now? Snap out of it!

"I should just do what mother tells me to do!", he thought to himself, "I don't actually mind the cape though!"

Behind his very formal dark blue suit was a neon blue cape, kind of resembling the one Satan was wearing, the edges of the cape, a bit ripped up and burned, added a nice effect too!

So cool!

While Rin was busy admiring his suit the kings that were sitting behind the High King were sweating like crazy.

The King of Fire scooched over to the King of Spirits, who looked very disinterested at the high podium.

"Ne Azazel bro, do you think baby bro will mess it up?"

Azazel spared a quick glance at his childish brother beside him and fixed his glasses that he borrowed from Samael. He found them quite fashionable!

"Don't be ridiculous Iblis!" he scolded Iblis quietly, which made his Iblis pout in return.

"He will definitely screw up."

"Pfffff-!", that made the King of Fire crack up, totally forgetting the ceremony.

Instantly the two of them felt a very scary and familiar aura engulf them. They both looked in the same direction. Their mother smiling gently at them is not a good sign. Not a good sign at all!! She mouthed something to them and somehow smiled even more. They instantly paled.

"Be quiet, boys."

Mother spare us!

* * *

"Now I present to you, the ninth king!", Satan finally stated.

The elegantly carved navy blue door opened slowly. A neon blue carpet rolled out and stopped exactly at the feet of Satan. 

The door completely opened with Rin standing in all his glory. With his raven wings unfurled and cape ablaze blue fire dancing around the edge-

Wait... blue fire???

This has once again caused an uproar.

"The royal blue flames?!"

"Impossible!"

"How can this be true?!"

"Finally! Someone has inherited the blue flames of our High King!"

"Rejoice! Our king has born a successor!"

"A successor!"

"Rejoice!"

"Ninth king of Gehenna our crown prince!"

_"Ninth king of Gehenna our crown prince!"_

**"Ninth king of Gehenna our crown prince!"**

Many demons started to chant and stomp creating a small earthquake. It's time! The destined crown prince was there! In front of their very eyes/eye!

The cheering continued until Satan raised his hand that made all demons tense up and quiet down instantly. 

No one dared to utter a single word.

The High King looked at the ninth king and gestured for him to come forward.

Rin sensed the tense atmosphere and gulped. Well, here it goes.

Walking slowly towards his father that, for once, was looking very seriously at him and made sure to not make any dumb mistakes. I mean, it's just walking, right?

Every step he made was heard seemed to be the only sound there was, creaking. 

Finally, he stood in front of his father and kneeled with his head bowed. 

Satan spread out his wings. They were much bigger than the prince's wings and looked very majestic, with blue fire engulfing its whole frame.

He placed his two snow-white hands on his son's head. It was time.

Every demon, slaves, commoners, nobles, kings and queens alike, spread their hands forward, exactly how Satan is.

"I am willing to show you the way."

** _"I am willing to be shown the way by thou king."_ **

"I am willing to be the one guiding you."

** _"I am willing to be guided by thou."_ **

"I am willing to let you serve me."

** _"I am willing to serve thou, king."_ **

"I am willing to let you rule as a king."

** _"I am willing to accept thou as my king"_ **

The demons chanted after the High King. This was the special ritual only served for the crown prince. The demons have been waiting for the day they finally utter these words! They were very polite, unlike their High King who calls the crown prince per "you". But he's his son after all! The crown prince of Gehenna!

Rin stood up and walked up to the edge of the podium. 

"I am willing to show you the way!

I am willing to guide you!

I am willing to let you serve me!", Rin paused and glanced at all the demons present. From big demons to demons as small as an insect. From the demons flying in the dark blue sky and the demons standing on the ground.

"I am willing to be your new king!"


	4. Just leave me alone, will you!

**Summary for the Chapter:**

> After the crowning Rin just wants to get to bed, but certain demon brothers get ahold of him... he certainly isn't pleased.

**Notes for the Chapter:**

> I AM BACK! After a few days of writers block, I finally know what words to write!
> 
> Enjoy~

A deafening cheer shook the earth.

Their crown prince is here! He will help them! He can turn things around!

Satan suddenly appeared next to Rin, placing a golden crown with an ice blue gem embedded in the middle of the newly crowned king's head.

"From now on, he is the ninth prince of the territory "The frozen forest of the shape-shifting shadows"! Since he has multiple special features he will have a very special royal title!"

The High King placed both of his hands on Rin's shoulders.

"The crown prince of Gehenna!"

With that blue flames engulfed them both, the High Queen and the rest of the kings of the territories, not leaving a single trace of them behind other than a burned mark on where they previously stood on. That left the other nobles that were so lucky to be invited to stand there to depart on their own, through the beautifully carved door Rin previously walked on. 

The demons looked at each other, stranger or not, and celebrated together. Demons from different kins started getting together in groups, making their way to the celebratory room that their dear High King and their beloved crown prince had previously demolished. Luckily, they didn't know, or else they would have thought of him _very_ differently...

While the demons of different kins departed, the royal family landed in the middle of a room. Satan's study room to be exact. The eight older demon kings sighed with relief. The ceremony didn't go completely wrong!

Rin did it!

He didn't mess up!

The newly crowned king glared at them.

"Oi! What are you sighing for!"

Iblis suddenly teleported behind him and slapped his back.

Iblis: "Good job baby bro! You didn't mess up!"

Rin: "Hey, what does that mean!"

Beelzebub: "It means he didn't believe in you."

Rin: "Big bro, you said you would trust me!"

Iblis: "Beelzebub bro, stop spouting nonsense!"

Azazel: "It's true Rin."

Iblis: "Azazel bro, you're bullying me!"

Egyn: "Ne, Rin. You can believe me it's true! He even questioned you in the middle of the ceremony!"

Rin: "Iblis bro! How could you!"

Iblis: "Egyn, how can you say that! Of course I wouldn't doubt baby bro..."

Egyn: "Hehe, he's loosing confidence~"

Lucifer: "Little bro, how can you loose confidence that easily..."

Iblis: "Lucifer bro, they're bullies! How can you bully this little one without feeling ashamed!"

Astaroth: "You call being a few tens of thousands of years old being little? Childish."

Iblis: "Astaroth bro, not you too..."

Rin: "Guys..."

The siblings kept arguing, not noticing their other brother slipping away.

You guys are so childish! How were you able to reign a territory in the past thousands of years like this!?

Yuri tapped her husband on his shoulder.

"Ne, they got it from you."

"...don't remind me."

* * *

Rin yawned as he stumbled his way to his bedroom.

The ceremony was supposed to give him some powers. Why did he feel so weak?

Finally, he was in front of his door.

Why was his house so big?! He spent a total of half an hour to walk to his room. Hai, he was spent.

He wiped his eyes again. Very spent. The crown prince can finally enjoy his peace and quiet and sleep after a long day. 

Opening the door, Rin finally remembered in what family he was born in.

Iblis: "**BRO**! You left me to the wolves! How could you!"

Azazel: "You deserve it."

Astaroth: "And now you dragged us in here to get revenge. Childish."

Beelzebub: "Hehe, what did you expect. It's Iblis we're talking about!"

Lucifer: "To even drag us, busy territory lords, to get revenge on you little brother is disappointing. How can you lose that much confidence? To even fear your little brother..."

Amaimon: "Sigh."

Rin slapped his forehead. Oh boy, not again.

He looked around the room and saw Egyn leaning against the wall and raised his eyebrow.

Egyn: "What? I'm just enjoying the show."

Rin: "..."

_At least help me would you?!_

**Notes for the Chapter:**

> The personalities of the demon kings are all made up by me, except Amaimon's, which I complied to canon.
> 
> This is stilllllll not edited because I don't know what betas are .-.


End file.
